The terrorist attacks of September 11, 2001 placed additional security concerns on the U.S. pipeline infrastructure. As a result, the Pipeline and Hazardous Materials Safety Administration (PHMSA) restricts access to the NPMS to federal, state, and local government agencies (including emergency responders). Government agencies are allowed access to pipeline data which falls in their jurisdiction. Pipeline operators are allowed access to their own pipeline data only. PHMSA is committed to providing pipeline related data to pipeline operators complying with integrity management programs and to community officials. The NPMS contains the following data:

Operators are required to update their NPMS data every year. Effective October 1, 2015 gas transmission pipeline and LNG plant operators are required submit to the NPMS by March 15 and hazardous liquid pipeline operators are required to submit to the NPMS by June 15. The submitted data reflects conditions in the field as of December 31 of the previous year. Data requests for updated NPMS data must follow the same procedures as first-time data requests.

All applicants are screened to ensure they are qualified to access NPMS data.

Disclaimer: National Pipeline Mapping System (NPMS) data is compiled by the United States Department of Transportation, Pipeline and Hazardous Materials Safety Administration, Office of Pipeline Safety. The data is compiled from mandatory submissions made by pipeline and LNG plant operators and voluntary submissions made by breakout tank operators. The data is processed by private contractors. Neither the United States government nor any party involved in the creation and compilation of NPMS data and maps guarantees the accuracy or completeness of the product. NPMS data should be considered no more accurate than +/- 500 feet and must never be used as a substitute for contacting the appropriate one-call center prior to digging.